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ConFoo Call for Papers is Open

ConFoo is once more seeking passionate speakers for the upcoming conference.

The event is happening in Montreal, Canada, between February 24th and 26th, 2016. It is an exciting conference for web developers with speakers from all over the world. It unites many web programming languages under one roof, as well as other topics related to web development. The call for papers closes on September 20th.

ConFoo renews 50% of its speakers each year. If you’re new to this conference, you should definitely submit.

If you would just like to attend, there is a discount until October 13th.

Howto: Online Upgrade of MariaDB Galera Cluster 5.5 to MariaDB 10

The MariaDB team released a GA version of MariaDB Galera Cluster 10 in June 2014. MariaDB 10 is the equivalent of MySQL 5.6, and therefore, packed with lots of great features. 

In this blog post, we’ll look into how to perform an online upgrade to MariaDB Galera Cluster 10. At the time of writing, MariaDB 10.1 was still in beta so the instructions in this blog are applicable to MariaDB 10.0. If you are running the Codership build of Galera (Galera Cluster for MySQL), you might be interested in the online upgrade to MySQL 5.6 instead. 

Offline Upgrade

An offline upgrade requires downtime, but it is more straightforward. If you can afford a maintenance window, this is probably a safer way to reduce the risk of upgrade failures. The major steps consists of stopping the cluster, upgrading all …

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The Primary Component in Galera Cluster

In this post, we will describe the Primary Component, a central concept in how Galera ensures that there is no opportunity for database inconsistency or divergence between the nodes in case of a network split.

What is the Primary Component?

The Primary Component is that set of Galera nodes that can communicate with each other over the network and contains the majority of the nodes. In case of a network partition, it is those nodes that can safely commit a transaction. A cluster can only have one such set of nodes, as there can only be one majority. No other set of nodes will commit transactions, thus removing the possibility of two parts of the cluster committing different transactions and thus diverging and becoming inconsistent.

The Healthy Cluster

In a healthy cluster, all nodes nodes can communicate with each other, so they all belong to the Primary Component and can all receive updates. There are no …

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New MySQL Sandbox 3.1 - GitHub, and usability

I have three pieces of information to share about MySQL::Sandbox:

  • Version 3.1.0 has migrated from Launchpad to GitHub
  • This version is released under the Apache license. Both these changes are meant to improve and promote cooperation on the project.
  • There is an important change related to usability. When using replication with MySQL::Sandbox and MySQL 5.6+, the server UUIDs become more readable (see below).

First, some words on the location changes. About two years ago, I started plans for a rewrite of MySQL::Sandbox. Then, I had some unexpected changes, which involved moving home to a different continent twice within twelve months. The project …

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Comment on Should I worry about the Query Cache in Aurora ? by Should I worry about the Query Cache in Aurora ? | MySQL

[…] PlanetMySQL Voting: Vote UP / Vote DOWN Full article:Should I worry about the Query Cache in Aurora ? […]

Swap Endian
CREATE FUNCTION SWAP_ENDIAN(inString text)
RETURNS TEXT
DETERMINISTIC
-- Expects a hex string: AbCdEf
-- Returns the string swapped for endianness: EfCdAb

BEGIN
  DECLARE position INT DEFAULT 1;
  DECLARE holder TEXT DEFAULT '';

  WHILE position 

So you can do things like:

SELECT
  FROM_UNIXTIME(
    CONV(
      SWAP_ENDIAN(
        SUBSTRING(
          HEX(
            FROM_BASE64(
              'Yk3XVQ8pAAAAZgAAAGoAAAAAAAQANS4xLjczLWxvZwAAAAAABBAAAAAAAAAAAAAAAA'
              'AAAAAAAAAAAAAAAAAAAAAAAABiTddVEzgNAAgAEgAEBAQEEgAAUwAEGggAAAAICAgC'
            )
          ), 1, 8
        )
      ), 16, 10)
  ) AS event_timestamp;
Tungsten Replicator moved to GitHub with Apache license

It had been in the making for long time. Google announced that Google Code would be closing, and since then the Continuent team has been hard at work to handle the transition. You can guess it: this operation would have been quicker if it had been done by a small company like we were one year ago, but being part of a large corporation introduces some constraints that have affected our schedule.

However, our wish has always been, and still is, to keep Tungsten Replicator as an open source product, with full functionalities and with the full benefits that the open source development model offers.

Today, Tungsten Replicator is available on GitHub as …

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Advanced Query Tuning in MySQL 5.6 and MySQL 5.7 Webinar: Q&A

Thank you for attending my July 22 webinar titled “Advanced Query Tuning in MySQL 5.6 and 5.7” (my slides and a replay available here). As promised here is the list of questions and my answers (thank you for your great questions).

Q: Here is the explain example:

mysql> explain extended select id, site_id from test_index_id where site_id=1
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: test_index_id
         type: ref
possible_keys: key_site_id
          key: key_site_id
      key_len: 5
          ref: const
         rows: 1
     filtered: 100.00
        Extra: Using where; Using index

why is site_id a covered index for the query, given the fact that a) we are selecting “id”, b) key_site_id only …

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Should I worry about the Query Cache in Aurora ?

There are a lot of blog posts on the internet which warn you about using the Query Cache in MySQL.

I was surprised to see that the query cache was enabled in Aurora.

This was the size on a ‘db.r3.large’ instance.

On a ‘db.r3.2xlarge’  instance, it was set to 2460900352 i.e. 2.4GB

I am not sure, if amazon has done something to improve the query cache.

So, do run tests with Aurora and see if the cache suits you.

The Address Sanitizer Finds Bugs in TokuFT

This blog describes how the Address Sanitizer found bugs in the TokuFT (now PerconaFT) storage library.  TokuFT is the storage library used by the TokuDB for MySQL and TokuMX for MongoDB products.  TokuFT is currently tested with valgrind's memcheck tool.  However, memcheck is very slow compared to native execution, so memcheck is not always used for large tests.  This leads to missed bugs.

The Address Sanitizer is a memory …

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